The present invention relates to a method for adaptive knock control and a corresponding device.
German Published Patent Application No. 40 08 170 describes a characteristics map for the ignition angle retard that is used as a function of the operating parameters. When a specific characteristics map range is exited due to changes in the operating parameters, this characteristics map is then updated with the value of the ignition angle retard assumed prior to exiting the characteristics map range. If the operating parameters of the internal combustion engine change in such a manner that they correspond to a new characteristics map range for the ignition angle retard, the value already included in this new range is read out as the starting value for an ignition angle retard.
German Published Patent Application No. 195 32 504 describes a method in which, when a specific dynamic threshold in an operating parameter is exceeded, the characteristics map value of the new characteristics map range corresponding to the operating parameters is selected as the starting value for the ignition angle retard.
In contrast, the method according to the present invention and the corresponding device have the advantage that ignition angle jumps occurring as a result of a starting value being read out from a new characteristics map range under unfavorable conditions are minimized. Thus, there is only a minimal occurrence of torque jumps, which do not result in the loss of ride comfort.
Therefore, it is advantageous that the maximum allowable jump in the value of the ignition angle adjustment is actually achieved, because, as such, the ignition angle can be adapted as quickly as possible to the knock limit in this range. It is also advantageous to provide the load and the engine speed as operating parameters that are also subject to a dynamic, because these two operating parameters most directly describe the state of the internal combustion engine. It is equally advantageous to provide an additional ignition retard that is dependent upon the intensity of the dynamic. Thus, an additional knocking tendency of the internal combustion engine only occurring as a result of a strong dynamic can be countered. It is also advantageous that an adaptive characteristics map for ignition angle adjustment is provided for every cylinder, so that the ignition angle can be individually adjusted for each cylinder. Further advantages result from the following description.